(P7) Perimeter-Area Ratio

p_ij =    perimeter (m) of patch ij.

a_ij =     area (m²) of patch ij.

Description

PARA equals the ratio of the patch perimeter (m) to area (m²).[p_ij =intTrue+intBack+extTrue+extBack+extLike]

Units 

None

Range

PARA > 0, without limit.

Comments

Perimeter-area ratio is a simple measure of shape complexity, but without standardization to a simple Euclidean shape (e.g., square). A problem with this metric as a shape index is that it varies with the size of the patch. For example, holding shape constant, an increase in patch size will cause a decrease in the perimeter-area ratio.